This protocol is a a multicenter collaborative trial of home infant apnea monitors. These devices are used to monitor breathing and heart rate in infants thought to be at risk for sudden infant death syndrome (SIDS). This study will yield extensive descriptive information regarding the efficacy of apnea monitors, their accurracy, and the ability of these devices to detect clinically important events. Neurodevelopmental assessments are conducted on infants until the age of 2 years.